mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
62b0194368
The RISC-V ISA defines a per-hart real-time clock and timer, which is present on all systems. The clock is accessed via the 'rdtime' pseudo-instruction (which reads a CSR), and the timer is set via an SBI call. Contains various improvements from Atish Patra <atish.patra@wdc.com>. Signed-off-by: Dmitriy Cherkasov <dmitriy@oss-tech.org> Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com> [hch: remove dead code, add SPDX tags, used riscv_of_processor_hart(), minor cleanups, merged hotplug cpu support and other improvements from Atish] Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Atish Patra <atish.patra@wdc.com> Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
60 lines
1.4 KiB
C
60 lines
1.4 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Copyright (C) 2012 Regents of the University of California
|
|
* Copyright (C) 2017 SiFive
|
|
* Copyright (C) 2018 Christoph Hellwig
|
|
*/
|
|
|
|
#include <linux/interrupt.h>
|
|
#include <linux/irqchip.h>
|
|
#include <linux/irqdomain.h>
|
|
|
|
/*
|
|
* Possible interrupt causes:
|
|
*/
|
|
#define INTERRUPT_CAUSE_SOFTWARE 1
|
|
#define INTERRUPT_CAUSE_TIMER 5
|
|
#define INTERRUPT_CAUSE_EXTERNAL 9
|
|
|
|
/*
|
|
* The high order bit of the trap cause register is always set for
|
|
* interrupts, which allows us to differentiate them from exceptions
|
|
* quickly. The INTERRUPT_CAUSE_* macros don't contain that bit, so we
|
|
* need to mask it off.
|
|
*/
|
|
#define INTERRUPT_CAUSE_FLAG (1UL << (__riscv_xlen - 1))
|
|
|
|
asmlinkage void __irq_entry do_IRQ(struct pt_regs *regs, unsigned long cause)
|
|
{
|
|
struct pt_regs *old_regs = set_irq_regs(regs);
|
|
|
|
irq_enter();
|
|
switch (cause & ~INTERRUPT_CAUSE_FLAG) {
|
|
case INTERRUPT_CAUSE_TIMER:
|
|
riscv_timer_interrupt();
|
|
break;
|
|
#ifdef CONFIG_SMP
|
|
case INTERRUPT_CAUSE_SOFTWARE:
|
|
/*
|
|
* We only use software interrupts to pass IPIs, so if a non-SMP
|
|
* system gets one, then we don't know what to do.
|
|
*/
|
|
riscv_software_interrupt();
|
|
break;
|
|
#endif
|
|
case INTERRUPT_CAUSE_EXTERNAL:
|
|
handle_arch_irq(regs);
|
|
break;
|
|
default:
|
|
panic("unexpected interrupt cause");
|
|
}
|
|
irq_exit();
|
|
|
|
set_irq_regs(old_regs);
|
|
}
|
|
|
|
void __init init_IRQ(void)
|
|
{
|
|
irqchip_init();
|
|
}
|